Glass options for Southern NH

I'm in Southern NH and my house has wide open exposure, with most windows facing East or West. Only 2 face South, and 4 face North.

Right now, the contenders are Gorell 5100, Okna 500 or maybe 800, and Simonton Asure or 5500.

I'm a little concerned about thermal stress on the glass, as my East/West exposure heats and cools dramatically over the course of most days. Should I insist on Superspacer? If I should, I'll knock Asure out of contention as that is not an option in that line.

From what I read, a triple pane 5100's performance is roughly equivalent to a double pane 500/800 - true?

Can I tailor glass for each exposure? Perhaps triple panes facing North, and double pane for East and West to pick up solar gain in winter? Any thoughts much appreciated!

I wouldn't worry about any of the glass packages not tolerating the heat or cold very well.

Yes, a non-metallic spacer will have a better condensation resistance and will not be as likely to sweat on the edges of the sash where conduction losses are higher, however, the rest of the glass performance should do just fine.

Are non-metallic spacers preferable, yes as well.

Tough to say how the performance comparison shakes out without know exactly what package was quoted to you in the 5100.

That should be pretty close assuming it is the EMIII. The Okna 500 gets a .25 from double pane while the Gorell is around .24 (give or take .01) with the EMIII package. Both are very good choices for your climate.

+1

Might be worth considering that the Okna window at a U-Factor of 0.25 in double pane would probably perform a bit better given the fact that it will allow for a bit more passive solar in this application than the triple pane Gorell.